Underarm Cyst

Has anyone ever had a cyst pop up under their arm in the armpit? I had one pop up about a month ago that was sore and swollen. It began to get bigger so I went to the doctor and was put on an antibiotic. The size went down but now it's coming back. I have a scar in my armpit where I had my breat augmentation surgery two years ago, could this be related to scar tissue? Anyone have this happen or have any feedback?